In the past, a display processing device that downloads an application program (hereafter, simply “application”) and displays an image based on that application has been provided, a representative example being a digital television terminal.
Technology regarding such a display processing device, which downloads an application and executes the application, is prescribed in Non-Patent Reference 1 (the DVB-MHP standard (ETSITS 101812 DVB-MHP specifications V 1.0.2), which is the European digital television standard), Non-Patent References 2 and 3 (the Home Audio Video Interoperability (HAVi) standard, which is a standard for digital consumer A/V appliances), and so on, and is publicly-known technology. The DVB-MHP standard employs the AWT and the Java Media Framework (JMF), which are lava (R) class libraries, and the HAVi Level 2 GUI, as defined in the HAVi standard. In addition, the DVB-MHP standard prescribes an Application Program Interface (API), and through this API, a downloaded application can control a display processing device that includes an On-Screen Display (OSD) plane, a video plane, and a still plane. For details, refer to the DVB-MHP specifications and chapter 8 of the HAVi specifications.
Hereafter, a general overview shall be given regarding a display processing device used in the DVB-MHP standard.
FIG. 1 is a conceptual diagram showing a downloaded application 2410 and a display processing device 2420.
The display processing device 2420 is configured of an OSD control unit 2421, an OSD plane 2422, a video control unit 2431, a video plane 2432, a still control unit 2441, a still plane 2442, and a display 2450.
The OSD control unit 2421 is configured of software and provides an API so that the downloaded application 2410 can render graphics. Through this API, the OSD control unit 2421, which has been instructed to render graphics, renders the graphics, resulting in the generated rendered image being stored in the OSD plane 2422.
The OSD plane 2422 is configured of a memory or the like, and stores the rendered image generated by the OSD 2421.
The video control unit 2431 is configured of software and provides an API so that the downloaded application 2410 can reproduce video. Through this API, the video control unit 2431, which has been instructed to reproduce video, reproduces the video, and stores the reproduced video in the video plane 2432. Decoding a video signal sent as an MPEG-2 and converting it into a displayable format can be given as a specific example of video reproduction.
The video plane 2432 is configured of a memory or the like, and stores the video reproduced by the video control unit 2431.
The still control unit 2441 is configured of software and provides an API so that the downloaded application 2410 can render a background image. Through this API, the still control unit 2441, which has been instructed to render a background image, renders the background image, and stores the generated background image in the still plane 2442. Decoding of MPEG-I data and single-color filling can be given as specific examples of processing for rendering a background image.
The still plane 2442 is configured of a memory or the like, and stores the background image generated by the still control unit 2441.
The display 2450 superimposes the image stored in the video plane 2432 on the image stored in the still plane 2442, and after that, further superimposes the image stored in the OSD plane on the previous superimposed image; the display 2450 then displays a final synthesized image.
FIG. 2 is a diagram showing each image synthesized by the display 2450 and the synthesized image that is ultimately displayed. Here, the images stored in the still plane 2442, the video plane 2432, and the OSD plane 2422 are synthesized and displayed.
FIG. 2 (1) is an image stored in the OSD plane 2422. In FIG. 2 (1), the OSD plane 2422 stores an image that includes graphics content 2501, which shows a list of channels, and graphics content 2502, which shows TV program details. Note that in this image, information indicating transparency is stored in the areas aside from the graphics content 2501 and 2502. Here, “graphics content” refers to figures, characters, or the like that are rendered in the OSD plane through the downloaded application 2410 calling the API.
FIG. 2 (2) is an image stored in the video plane 2432. In FIG. 2 (2), the video plane 2432 stores an image that includes video 2503, which is reproduced at ¼ the size of the screen in the upper-right corner of the screen. In this image, information indicating transparency is stored in the areas aside from the video 2503.
FIG. 2 (3) is an image stored in the still plane 2442. In FIG. 2 (3), the still plane 2442 stores a background 2504, which is filled with a single color, as an image.
FIG. 2 (4) shows the result of the display 2450 synthesizing the image stored in the OSD plane 2422 shown in FIG. 2 (1), the image stored in the video plane 2432 shown in FIG. 2 (2), and the image stored in the still plane 2442 shown in FIG. 2 (3). Specifically, the display 2450 superimposes the video 2503 stored in the video plane, as shown in FIG. 2 (2), on the background 2504 stored in the still plane 2442, as shown in FIG. 2 (3); the display 2450 then superimposes the graphics contents 2501 and 2502 stored in the OSD plane 2422 shown in FIG. 2 (1), and displays the final image.    Non-Patent Reference 1: ETSITS 101812 DVB-MHP Specifications v1.0.2    Non-Patent Reference 2: HAVi v1.1, Chapter 8, May 15, 2001    Non-Patent Reference 3: HAVi v1.1 Java (R) L2 APIs, May 15, 2001